Fuel oil compositions



of filters, screens and lines.

structural formula contain two Patented Jan. 12, 1954 FUEL OIL COMPOSITIONS Richard D. Stayner and Robert A. Stayner,

Berkeley, Calif., assi search Corporation,

7 Claims.

1 The present invention is concerned with improved hydrocarbon fuels and, more particularly,

' with hydrocarbon fuels having improved proper- 4 ties as burner fuels and diesel engine fuels.

In the production of burner fuels and diesel engine fuels it is desirable, economically, to employ considerable quantities of cracked refinery stocks. Such stocks are becoming more and more available due to the ever increasing use of thermal and catalytic cracking processes in petroleum refinery operations. When employed in burner fuels and diesel engine fuels these stocks have the disadvantage of forming particles of sludge or gum which tend to deposit and cause plugging The necessity for frequent interruptions of burner and diesel engine service to replace or unplug clogged filters and screens constitutes a serious problem.

Burner and diesel engine fuel systems ordinarily contain certain amounts of water due to vapor condensation. The presence of this water tends to accelerate the formation of filter plugging gum and sludge in burner and diesel fuels containing cracked stocks and also causes rusting of exposed ferrous metal surfaces, which rust, in turn, eventually loosens and clogs the filters and lines.

Pursuant to the present invention, it has been discovered that by the addition of a small amount of an N,N-di-(alkyl aryl methylene) -N-alky1- ammonium alkane sulfonate to normally liquid hydrocarbon fuels, any tendency of the fuel to form filter clogging particles of sludge or gum is substantially overcome. Such hydrocarbon fuel compositions, in addition, have the effect of inhibiting rusting of ferrous metal surfaces with which they come in contact, thus substantiallyeliminating rust particles that may also lead to clogging of fuel oil systems.

The N-N-di-(alkyl aryl methylene)-Nalkylammonium alkane sulfonates employed in the ,fuel compositions may be illustrated by the following structural formula:

RrArOHa fi'r-m-soQ Ramon. R3

wherein R1 and R2 are alkyl groups of from 9 to 18 carbon atoms, Ar is an aryl hydrocarbon group, R3 is an alkyl group of from 1 to '7 carbon atoms, and R4 is an alkylene group of from 1 to '7 carbon atoms.

The compounds as illustrated in the above aryl or alkaryl groups, each of which is connected by a. methylene linkage to the nitrogen. Examples of suitable aryl groups are benzene, naphthalene, anthragnors to California Re- San Francisco, Calif., a corporation of Delaware No Drawing. Application September 25, 1951, Serial No. 248.280

cene, toluene, xylene, mesitylene, etc., with benzene and toluene being preferred for their availability and the high degree of effectiveness characteristic of the compounds containing them. The nuclear alkyl substituents may be straightchain or branched-chain in nature and may vary from 9 to 18 carbon atoms in length. The alkyl groups may be derived from halogenated hydrocarbons, aliphatic alcohols and olefins including cracked petroleum fractions and polymers of ethylene, propylene and butylene. For present purposes propylene polymers containing from 12 to 15 carbon atoms per molecule are preferred because of their chemical stability derived from the characteristically moderate chain-branching of propylene polymers in general.

The above compounds may be prepared by reacting a molar excess of an alkyl aryl methylene halide with an N-alkyl amino alkane sulfonic acid in the presence of a neutralizing agent. Further and more specific details as to their preparation may be found in copending U. S. application No. 248,279, filed September 25, 1951, of Richard D. Stayner.

, In the above structural formula illustrating the invention, that portion derived from the N-alkyl amino alkane sulfonate reactant is represented by the group:

Suitable N-alkyl amino alkane sulfonates are sodium N-methyl amino ethane sulfonate, otherwise known as sodium N-methyl taurate, sodium -ethyl amino ethane sulfonate, potassium N- ethyl 2-amino propane sulfonate, sodium N-butyl amino butane sulfonate, sodium N-hexyl amino cyclohexane sulfonate, etc. Presently preferred is sodium N-methyl amino ethane sulfonate or sodium N-methyl taurate because of its common availability and its particular suitability to the invention.

-N,N-dialkylbenzyl-N-methyl taurines constituting the preferred additives of the invention are illustrated by the formula:

wherein R1 and m are alkyl groups of from 9 to 18 carbon atoms, R is a hydrogen or methyl group, and x is an integer of from 1, 2, 3.

Thispreferred group of additivesmaybe prepared by chloromethylating nuclear alkyl derivatives of benzene, toluene or xylene, for example. A molar excess of the chloromethyl derivative, and preferably at least 2 molar proportions thereof, may then be reacted with sodium =N-methyl taurate at a temperature of fromabout 50..t 100 C. in the presence of a neutralizing agent suchas sodium hydroxide, sodium bicarbonate,.;sod-ium carbonate, lime, etc.

Specific examples of N,N-di-(alkyl aryl methylene) -N-alkyl-ammonium alkane sulfonates-gwithin the above generic disclosures which aresuitable for incorporation in fuel oil compositionsaccording to the invention are N,N-di-(nonylben- -zyl) -.N-methyl-ammonium ethane sulfonate, otherwise. known as N,N.-di- (nonylbenzyl) N.-.methyl .taurine; N,N-di- (dodecylbenzyl) .N- methyl taurine; N,N-di-(decyl .methyl LbenzyDrN-methyl taurine; N,N- di- (.dodecylv methyl vbenzyl) .,N- ethyl cammonium propane sulfonate; .,N,Nedi-.(penta- ;decyl .benzyl) -N-butyl-ammonium butane .sul- .f-onate; N,N-di-(octadecyl di-.methyl .benzyl): .hexyl-ammonium cyclohexane sulfonate; N,N-di- =,(nonyl naphthyl methylene) -N-propyl-ammoinium .hexane vsulfonate; and N.N..di-.(.dodecyl methyl naphthyl methylene) .-N-methyl-ammo- ..nium ethane sulfonate, otherwise known. as ,N,N- di-(dodecyl methyl naphthyl methylene) -N methyl taurine,. etc.

The hydrocarbon fuel base stocks suitable for .use.inthe improved fuel oil compositions of the ;.;present invention may be described broadly. as petroleum distillatesboiling.inthe. range of from about 350 F. to about 750.F. such distillates are -.ordinarily characterized. by anA. P.,I. gravity-of ....at. least 20, and usually at least 25. The base *stocks may be either :straight-run ,distillates or cracked distillates. The presentinventionfinds .its greatest utility in hydrocarbon fuels of 1 the -qpreceding .types which contain substantial .amounts of cracked distillates. .Without the additives of this invention such fuels form appreciable amounts of filter plugging sludge and gum which render them unsuitable for use in operations where uninterrupted service is desired, as is the case with most present-day operations.

Very small amounts of the N,N-di-(alkyl aryl m'ethylene)-N-alkyl-ammonium alkane sulfonates, in the order of 1% by weight or less; have been found to be entirely effective'to -prevent line and filter clogging and to inhibit rusting when "water is present in the system. Amounts in the range of from 0.001 to0.20'per cent by'weight "of the total fuel areparticularlysuitable'when the preferred N,N-di alkyl benzyl'n-methyl tau- 'rines' having from 9 to 18 carbon-atoms in each of thealkyl groups are employed. Proportions inthe range of from 0.005 to 0.015 percent by weight are inost' preferred in the more specific embodiments of the invention.

In order to facilitate evaluation of the improved fuel oil compositions of the .present invention and avoid an enormous outlay of time and material, a

rapid test method for determining filter plugging characteristics was developed. The results of this test method have been found to correlate well with actualfieldtests using regular fuel oil burners and diesel engines. Theiest is carried out by mixing 500 ml. of a fuel composition containing 0.01% by weight of additive with .500 ml. of Water containing 102 parts per million hardness calculated as calcium and magnesium carbonates, twothirds being calcium carbonate. The fuel oil composition and Water are shaken in a separatory funnel for 30seconds, at the end .of which they are allowed to. stand. for I0.minutes. SAt this point a phase separation occurs and an upper oil layer and a lower water layer are obtained, usually separated by an opaque cuff at their interface. This interface 'cuff is then filtered through a fritted glasscruciblewithmhe aid of a vacuum. Only as much oil and: water are filtered as are necessary to .assurecomplete-extraction of the cuff, usually ;about:25.-ml. =I-Iowever, in cases of sereve emulsions the entire contents of the separatory funne1'-'-may have'to*'be filtered. The resultant discoloration of crucible met by the particles of gum randzsluidge deposited is used as a comparative measure of the hydrocarbon fuels tendency to a plug filters and screens.

In the comparison the .filter .is. compared --with a standard. series .of.11filters preparedyin.a,simi- V lar manner .fromifuels of vknown.filter,pluggir ig :tendency. The standard-filtersare, numbered 0 .to -10, the higher numbers being .identified 'with the heavier deposits. .For. convenience, the rating .given a particulartest sample istermed its interface deposit rating .(IFD), and denotes the number of the filter-in the. standard series .with-whichit compares in amount of filter -.deposit.

Table I," which follows shows the IE'D values of a number of fuel .oil :;compositions;.-according to the present "invention, :-as fcomparedtwith 'Pa standard diesel or burner 'fuel. The these *1 fuel employed in each case was a"mixture-"of equal parts of straight 'run distillate from a'waxy base crude boiling intherange of from 384 Rte-"675 F; and 'a Thermofor catalytic cracked fraction 'boilingin the range offrom' 376;F."to'.5"66 F.

1 'N,N-di-(Oiz-polypropylenebenzyl)-Nmethyltaurine. -N,N.-d -(C polypropylenebenzyl)-N:methyltaurine;

v 11$,N-dikerylbenzyl-n-methyltaurine one The data .in'Table lclearlyshows the marked superiority of the improved hydrocarbon v fuel compositions. according to the present, invention over a conventional diesel ,.or burner fuel. .iRuns .1,.- 2' and. 3 each show .;that very littleior.;no.:filter deposit is obtained from fuel oil: compositions containing .a 1 representative N;N.-.di-.(alkyl t aryl methylene) -N-alkyl-ammonium alkane z-sulfonate, whereas the fuel oil base stock itself gives an extremely high filter-deposit.

The fuel oil compositions of the present invention were also tested for their rust inhibiting properties. The tests were car'riedoutin accordance with the procedure outlined in ASTM Method-'D-665-47T. steel spindleswere immersed in "an'agitated 'distilled'water andfuel oil mixture containing 0.001% .by weightof additiveand in an agitatedsea waterand fueloilmixturecon- .taining.0'.005% .by weightzof additive. The-base stockinel was-tested in-a similar fashion. The results.- of .these :tests were as .follows:

TABLE II Anti-rust properties R Auti-rgst s t on v rating isca we er- No. Addmve tilled Water oil mixture oil mixture 1 N,N-di-(Org-polypropylene No rust N rust.

benzyl)-N-methyltaurine. 2. N,N-di- (Cg-polypropylene; Light rust... D0.

benzyl) -N-methyltaurine. 3. N,N-dikery1benzy1-N methdo 1 yltaurine. 4. None Severe rust Severe rust.

From the above tests it will be readily observed that the improved fuel oil compositions of this invention possess remarkable rust inhibiting properties as compared to ordinary diesel or burner fuels.

The fuel oil compositions according to the present invention may contain other fuel oil additives in addition to the N,N-di-(alky1 aryl methylene) -N-alkyl-ammonium alkane sulfonates. Such additives include: lecithin; oil-soluble alkyl aryl polyglycol ethers, such as didodecyl phenyl dodecaethylene glycol ether; oil-soluble sulfonates, such as the lead salts of petroleum sulfonic acids containing from about to carbon atoms per molecule; oil-soluble naphthenates, such as the alkali metal and lead salts of petroleum naphthenic acids; alkali metal and lead salts of alkyl phenol di-sulfides.

We claim:

1. A hydrocarbon fuel oil composition containing a small amount sufiicient to inhibit line and filter clogging and corrosion of an N,N-di-(alkyl aryl methylene) -N-alkyl-ammonium alkane sulfonate in which the alkyl radical of the alkyl aryl methylene groups contains from 9 to 18 carbon atoms, the N-alkyl radical contains from 1 to 7 carbon atoms and the alkane group contains from 1 to '7 carbon atoms.

2. A hydrocarbon fuel oil composition contain- 6 ing a small amount sufficient to inhibit line and filter clogging and corrosion of an N,N-di-alkyl benzyl N-methyl taurine having from 9 to 18 carbon atoms in each of the alkyl groups.

3. A hydrocarbon fuel oil composition containing a small amount not exceeding 1% by weight of an N,N-di-alkyl benzyl N-methyl taurine having from 9 to 18 carbon atoms in each of the alkyl groups.

4. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil boiling in the range of from about 350 F. to about 750 F. and a small amount not exceeding 1% by weight of an N,N-di-alkyl benzyl N-methyl taurine having from 9to 18 carbon atoms in each of the alkyl groups.

5. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil boiling in the range of from about 350 F. to about "250 F. and from 0.005 to 0.015 per cent by weight of an N,N-di-alkyl benzyl N-methyl taurine having from 9 to 18 carbon atoms in each of the alkyl groups.

6. A hydrocarbon fuel oil composition comprising a major proportion of a normally liquid hydrocarbon fuel oil boiling in the range of from about 350 F. to about 750 F. and from 0.005 to 0.015 per cent by weight of an N,N-di-alkyl benzyl N-methyl taurine having a propylene polymer of 12 to 15 carbon atoms as each of its alkyl groups.

'7. A hydrocarbon fuel oil composition as described in claim 6, wherein the normally liquid hydrocarbon fuel oil contains a substantial proportion of cracked petroleum distillate.

\ RICHARD D. STAYNER.

ROBERT A. STAYNER.

References Cited in the file of this patent UNITED STATES PATENTS Number 2,433,997 Linch 

1. A HYDROCARBON FUEL OIL COMPOSITION CONTAINING A SMALL AMOUNT SUFFICIENT TO INHIBIT LINE AND FILTER CLOGGING AND CORROSION OF AN N,N-DI-(ALKYL ARYL METHYLENE)-N-ALKYL-AMMONIUM ALKANE SULFONATE IN WHICH THE ALKYL RADICAL OF THE ALKYL ARYL METHYLENE GROUPS CONTAINS FROM 9 TO 18 CARBON ATOMS, THE N-ALKYL RADICAL CONTAINS FROM 1 TO 7 CARBOB ATOMS AND THE ALKANE GROUP CONTAINS FROM 1 TO 7 CARBON ATOMS. 